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Bridgette Steffen writes "In attempt to slow down desertification, a student at London's Architectural Association has proposed a 6000 km sandstone wall that will not only act as a break across the Sahara Desert, but also serve as refugee shelter. Last fall it won first prize in the Holcim Foundation's Awards for Sustainable Construction, and will use bacteria to solidify the sandstone."

I do not think of myself as better than anyone else, but the Chinese (up to about 1600 CE, when the emperor pointed the country inward, to protect his power), Arabs/Egyptians/Babylonians (up to about 1500 CE, when the Sultan shut down all but one "University", in order to protect his power), Indians (who also seemed to regress after ) and Europeans (which includes the United States and Canada) (abortively starting with Greece and Rome, then from th

I was watching a program last night about the evolution of the planet, something about vulcanic activity and the superplume, and other things, as well as the evolution of the first landwalkers (tulogs?) that basically looked like a cross between crocodiles and fish, among all the changes in the environment, as well as mass ocean pollution (millions of years ago) killing a vast number of species.

When someone says nature is wise, they probably are romantizing how much "nature"/god? cares about our survival as a species but also don't want to be at the short end of the evolutionary stick when nature shows it' uncaring side and things change. I'm sure a man-made solutions to various things would be welcomed with open arms then.

Except it's usually the loopy lefty crunchy hippy types that actually most often anthropomorophize nature, assign it a personality, presume they know what it wants and how it should be, etc. You know it's true.

It's hardly anthropomorphic to describe nature as self correcting. Life on earth survived for what, like a billion years without modern man fucking it up? Pretty much a model for sustainability if you ask me.

Life as a whole survived, sure, but there were changes and extinctions, just as there are now. It's sustainable only in the way that everything is.

A balanced and closed ecosystem is naturally self correcting. Humans will prove no different. The available resources will be consumed, humans will die off in large numbers and a balance will be reached...

The late George Carlin described the above scenario as an Eden where man is a distant memory, and earth and styrofoam coexist happily.

It's hardly anthropomorphic to describe nature as self correcting. Life on earth survived for what, like a billion years without modern man fucking it up? Pretty much a model for sustainability if you ask me.

It's hardly anthropomorphic to describe nature as self correcting? Really? That implies that there is something to correct, which implies... . Not to mention describing some universal aspect of "Life" which the existence of an unbalanced humanity can "fuck up?" Sounds pretty anthropomorphized to me.

The crux of the matter seems to be, what do you mean by "self correcting?" I'm also unsure why you bring modern man into the equation. Surely you're aware of a multitude of previous mass extinctions? Surely you'

When people describe nature as self-correcting, they aren't usually referring to any inherent right or wrong. What gets corrected is imbalance, such as restoring a predator-prey system to equilibrium. It seems to me that discussing natural equilibria doesn't have to involve intent, purpose, morals, or anything else that would make it anthropomorphic to say that nature is self-correcting.

Right, I understand that (and almost didn't say what I did, how I did..) but then again, what is balance in nature--what does that mean?

I don't think there is any (forgive the term) "natural" state which is the proper and balanced state. Everything in nature is constantly in flux. Sure, to use the common example of the predator-prey equilibrium, that is sometimes the case. Sometimes the predators go extinct, sometimes prey go extinct, sometimes they both do.

It seems to me that it's far easier to look at life on Earth through the lens of evolutionary bubbles and crashes. It only seems self correcting because we want to apply some kind of order to it, when it reality, that's just the way the universe works. When a forest fire burns, it burns everything it can, until it's burned too much and dies out. That seems about the same level of self correcting to me.

Right, I understand that (and almost didn't say what I did, how I did..) but then again, what is balance in nature--what does that mean?

I think most people would consider "balance" as balanced in the favor of human habitation. As a species we are probably most interested in maintaining the organisms and ecosystems required for a comfortable human existence.

Well said. This is more or less what I was thinking; but I thought "hey it's 3:30a, maybe I'm making a really stupid leap in logic here, I'd best not make this post". You phrased it better than I would've in my sleepless state...

Yep. Just like when economists describe the free market as 'self-correcting', they don't mean there's a Big, All-Powerful Entity controlling it from the shadows, it's just that the system is such that minor changes will be met by opposite changes so that, overall, the system isn't affected on a large scale.

All some people are saying is, that like economies the 'self-correcting' system doesn't work as well for very large changes so when a single entity is far more greedy than it should, the entire system cou

Modern man is a part of the modern ecosystem, and occupies the top slot in the food chain. The planet is ours, period, and given technological advances it's highly unlikely that mankind will render the planet uninhabitable. Other species are not deserving of any special treatment. Get over it.

It's a matter of numbers. If the world were teeming with 7 billion lions, they would have a colossal influence on the world. The oxygen catastrophe [wikipedia.org] was the most profound environmental change caused by a population of living organisms.

Yeah, pesky humans, just because the desert ruins their crops and invades their village they feel the need to prevent it from doing so. Please people wise up and let Mother Nature in its infinite wisdom and consideration destroy all you have and ruin your life. For interfering with her might anger her.

Now if you'll excuse me I need to catch my plane to Holland, got some dams standing in the way of Mother Nature that need to be take care of.

The truth is more that interfering with nature is fairly futile, and it would be wiser to live in concert with it instead of fighting it all the time. For instance, we have a huge problem with fires in California. The natives just lived in baskets and set them on fire every year; regular fire keeps the forest healthy. The Pomo people lived in this area for at least ten thousand years so obviously they were doing something right. Their population was a lot lower, but you can still have centralized farming. Y

Considering that the desertification of the Sahara will eventually stop, and recede, and turn the desert back into a temperate climate when the Earth's precession realigns it to what it was like several thousand years ago.

Because we _caused_ the desert. Overpopulation, Overgrazing goats, digging for aquifers, using imported fertilizers, etc., helped destroy modest existing ecosystems that stabilized the soil and retained soil at the desert's border. Looked at over thousands of years of geological and archaelogical history, it seems clear that humans created or wildly expanded the deserts. There were amazing small areas that weren't overfarmed and avoided overpopulated, as experiments, and they showed up as remaining green and fertile as the desert grew right past them. It made the cause of desert growth quite clear.

I live in the south of Europe. It's highly likely that the Sahara crosses the Gibraltar Strait and comes knocking on my door. When that happens we'll all wish we have "interfered" more.

Up to the moment, the unbelievable stupidity (from politicians, companies and common people) in managing land goes to such an extent that makes me wonder if it's not intentional and there's a hidden conspiracy to turn my country into a desert.

So basically, Bacillus Pasteurii will be used to actually turn the sand into sandstone instead of waiting for thousands of years or using other kinds of walls.

To be honest, the part which is more interesting is the fact that desertification will be stopped by using a wall. Sure, the Slashdot summary used bacteria as a hook, but in all honesty, the wall is more important than the bacteria anyway, which is why there's only a small mention of the bacteria in the source article.

"The project seemed promising at first, as cucumbers, radishes and beans thrived on Nickel's test fields on the outskirts of Abu Dhabi. But the project also consumed vast numbers of worms -- 3,000 per square meter, to be exact -- which eventually made the project too costly for its sponsors."

I wonder what the costs between the two projects are or if they could be used in conjuction with each other (to lower costs) somehow.

A main part of the problem is that sand storms blow so much sand on surrounding grasslands, it kills the plants and spreads the desert. I don't see how a wall could help, unless it was kilometers high. It would need to stop this [wikimedia.org] ?

If most of the sand blows along the ground, it will collect at the base of the wall until it becomes a long sand dune. Since they are using bacteria, I could imagine them then solidifying the uppermost portion of the dune to make it higher. Rinse and repeat until your mountain (or hill) chain stops growing.

What second-generation Herberts? God, next you'll be telling me there's more than 6 Dune novels. HA! As if that could ever happen! Who'd write it? Frank Herbert's son and some worthless hack author? NO! It'll never happen!

I don't see how a wall could help, unless it was kilometers high. It would need to stop this ?

The vast majority of the sand is traveling very low to the ground. Sure, there's still a nice big dust cloud up high, but that big tall plume represents the least dense of the material, which is why it rises to the top.

You're essentially asking, "why have a sea wall if the very tops of the largest waves might still occasionally break over the top?"

I'm personally wondering what would prevent this wall from just catalyzing the formation of a massive sand dune, which would eventually rise above the wall, effectively rendering the wall useless. Unlike the Ocean, once sand rises up against the wall it isn't going to flow back out later.

Desert wall designed to stop sand, sea wall designed to stop ocean water. Waves will over-top a sea wall on occasion, but the water (what you're trying to keep out) doesn't stack up against the wall, it flows back out.

Wall designed to stop sand, as you said, catches sand. Eventually enough sand stacks up against the wall that sand is blown over the wall, making the wall useless.

Well they have the same problem with desertification in China, where the Gobi and 2 other smaller deserts are growing. Beijing gets regular sandstorms now because of this. It seems like mountains and yes, the Great Wall of China, has little effect in preventing these.

The main trouble I see (IMHO all this post, by the way) is not by the sand that flies higher than the wall as for the sand that get stopped at the bottom of the wall. I'd think that the sand that accumulates there will progresively form a half-dune. Once this happens, one of two might be the end:

The wall colapses due to the weight of the sand.

(more likely) the dune causes the wind to go uphill so the wall is rendered useless.

At the very least, the wall should be combined with other measures (growing plants

The main trouble is that where you used to have low water use grasses, you now have high water use crops. The result drains the water supplies, and food animals like goats are raised on the grasses, and they eat _everything_. So the stabilizing grasses are gone, the ground can't retain water. So what used to be stable grasslands is turned into desert.

The same sort of thing happened in Oklahoma in the 1930's in the USA, called the 'Dust Bowl'. Look it up.

Years ago I read about a plan to build a huge wall (for want of a better name) in central Australia. The wall would be thousands of metres high with a triangular cross section. In effect, an artificial north-south mountain range. The idea is that a lot of water vapour crosses Australia without precipitating because it never gets pushed to high enough altitudes to cool and condense. The article also suggested that the interior of the mountain could be used to store grains. I suppose these days we would put Afghan refugees in there as well.

I had the same de-certification read, only I was confounded about how bacteria could help teachers retain their credentials. (my brain processed it as a typical/. typo that got past the editors... just like all the rest)

>> How the hell are you supposed to pronounce that bizarre word, anyway?

I had the same though. It's either DESERT-ih-fih-KAY-shun, which... I dunno, just sounds wrong... Or, it's deh-ZERT-ih-fih-KAH-shun, but I think that would be spelled Dessertification - which is the transformation of food stuffs into dessert. Example:

"Overproduction of high fructose corn syrup by Big Food is responsible for the dessertification of American food, and Americans' resulting embiggenment."

The most information I could find is here [flickr.com] (the full-size images are pretty large) and here [blogspot.com].

It's hard to pick through the information, but is this scientifically viable? Or is this the random musings of an architecture student focusing only on the architecture side, and ignoring the biology side?

The desert exists because of a climate shift; presumably you would need to change the conditions which cause desertification and frankly, I don't think that we could create a wall of enough size to change air currents sufficiently.

is this the random musings of an architecture student focusing only on the architecture side, and ignoring the biology side?

I can't comment on the biology, but from a climate science perspective this is ridiculous. The designer has this vision of the Sahara as an endless sea of sand dunes, and thinks desertificaiton means the physical movement of these dunes to cover fertile areas. None of this is true.

This wall will do nothing to make it rain more in the Sahel, and it won't stop people from overgrazing o

You use irrigation techniques designed for low-water environments and strategically place human settlements in areas that you need planted. Plantings and irrigation anchor the soil and add more water to the system.

I know this is a scientific oversimplification, but I think it's been working well enough to shrink some of the Californian, Chinese, and Negev deserts.

As I understand the dune-grass in Northern Canada up through Oregon and Washington is invasive and a foreign species. It was originally planted as a way to stop erosion of some beaches and spread out of control almost overnight.
What's to prevent something like this happening / getting out of control and wrecking the natural ecosystem of our planet's deserts?

And here in Dixie we have "the weed that ate the south", also known as Kudzu [wikipedia.org]. In the south it was introduced to stop soil erosion and now that crap is everywhere. Telephone poles, abandoned buildings, pretty much anything standing still ends up covered in Kudzu. If you look at pics like this [wikipedia.org] ( which I have seen whole tracts of land, buildings and all, swallowed up like this) you see why we have to be careful about these great ideas of making the land better by introducing new elements like in TFA. What may

...by artists so full of themselves that they think can understand and harness something like stone-making bacteria. I know many of these types. They want to discuss ad nauseum every single scientific advancement and it's cultural implications, thinking that they can make some important contribution to the field. It's obvious these guys don't have a clue, as they think that an ice-nine scenario is something that, first nobody thought of, and second is even possible. These are the same people who hear about the LHC and think that there's a good chance that the universe might implode when they turn it on. As if the world works like it does in the politically motivated somewhat-sci-fi books that are all the rage in these circles.

Please, stay in the coffee shops in the village, discussing the importance of your latest pathetic attempt at relevance through putting mannequin arms in toilets bowls and calling it art.

Please, stay in the coffee shops in the village, discussing the importance of your latest pathetic attempt at relevance through putting mannequin arms in toilets bowls and calling it art.

Problem is, they have the internets in those coffee shops. So they stay in their version of starbucks but with their macbooks and iphones, their attempts at proving that a little bit of knowledge can be the most ridiculous thing spread.

I propose we build a wall out of bacteria and myspace pages to stop the "artistification" of the internet.

What is the evidence that there is any desertification? Where that is defined as deserts which are advancing, and whose advance is not containable by substitution of sustainable farming practices for unsustainable ones, such as over grazing by goats rather than mixed arable farming. That is, mixed crops and animal husbandry with attention to composting, manure and crop rotation.

There is no such evidence. All that is needed is sensible traditional mixed farming. And a lot less journalistic blather about

Where that is defined as deserts which are advancing, and whose advance is not containable by substitution of sustainable farming practices for unsustainable ones...

Kind of a trivial semantic argument right there. Whatever the cause, whatever you call it, it's not good for people who are going to be living in sand soon.

There is no such evidence. All that is needed is sensible traditional mixed farming. And a lot less journalistic blather about desertification that is not happening, global warming that is not happening, and how the one imaginary event is a consequence of the other imaginary event. And for well meaning idiots to stop subsidizing goats.

It would be nice if they practiced responsible farming, yes. Why isn't that happening already? Is there another problem upstream of unsustainable farming practices that's causing everyone to farm stupidly? Like maybe dumb economic systems that make it such that anyone who farms anything besides goats is quickly going to lose the farm and be replaced

And outlawing goats. And reducing human population in the neighboring desert states to sustainable levels, particularly avoiding urban growth. And stable enough governments in these regions to maintan such policies.

I'm afraid that while it's technologically sustainable farming you're suggesting, politically it's impossible. The populations there are not wealthy enough and do not give enough rights to women to curbe the population growth.

Droughts far worse than the infamous Sahel drought of the 1970s and 1980s are within normal climate variation for sub-Saharan West Africa, according to new research.

For the first time, scientists have developed an almost year-by-year record of the last 3,000 years of West African climate. In that period, droughts lasting 30 to 60 years were common. Surprisingly, however, these decades-long droughts were dwarfed by much more severe droughts lasting three to four times as long, scientists report in the 17 Apr